6.1.71
ह्रस्वस्य पिति कृति तुक्
Operational rule vidhi
A ह्रस्व letter that is followed by a कृत्-प्रत्यय that is पित् gets a तुगागम.
Word by word (padaccheda)
Target ṣaṣṭhī · ekavacanaRight context पिति saptamī · ekavacanaRight context saptamī · ekavacanaSubstitute / term prathamā · ekavacana
- Target Ṣaṣṭhī (6th case): names what gets replaced, "in place of X" (1.1.49 षष्ठी स्थानेयोगा).
- Right context Saptamī (7th case): "when X follows", the operation applies to what precedes (1.1.66 तस्मिन्निति निर्दिष्टे पूर्वस्य). Also a condition or domain ("in the sense of").
- Substitute / term Prathamā (1st case): in operational rules, the substitute or the thing introduced; in definitions, the term or its referent.
Dotted words are technical terms. Hover or tap one to see its card.
Pink letters are it-markers (anubandhas), tags dropped by 1.3.9. Hover or tap one for the rule that marks it, or try the it-letter finder.
Full reading
पिति तुक्
→ तुक् / पिति
Replace hrasvasya with tuk when piti kṛti follows. Inherited words (anuvṛtti) may add further conditions.
Commentary
To a root ending in a short vowel is added the augment त् (तुक्) when a कृत्-affix having an indicatory प् follows.
Thus अग्नि + चि + क्विप् = अग्निचित्, so also सोमसुत् ॥ Similarly प्रकृत्य and प्रहृत्य and उपस्तुत्य formed by the affix ल्यप् ॥ Why do we say "ending in a short vowel"? Observe आलूय, ग्रामणीः ॥ Why do we say "having an indicatory प"? Observe कूतम्, हृतम् ॥ Why do we say "a krit affix"? Observe पटुतरः, पटुतमः, with the Taddhita-affixes तरप् and तमप् ॥ In the compound ग्रामणिकुलम्, though the root is made short, yet there is no augment तुक्, in as much as the rule by which the root has been shortened is a Bahiranga rule, and the present rule is an Antaranga one. The maxim is असिद्धं बहिरङ्गमन्तरङ्गे ॥ "That which is Bahiranga is regarded as not having taken effect, or as not existing, when that which is Antaranga is to take effect".
Śrīśa Chandra Vasu, The Ashtadhyayi of Panini (1897), via ashtadhyayi.com.